Allow the user to forward the same message to multiple rooms at once

This will send the item to the rooms in order they were chosen and only deep link
into the target room if single, otherwise it will just dismiss the forwarding screen
after sending.

ElementX/Sources/Screens/MessageForwardingScreen/MessageForwardingScreenModels.swift

@@ -11,12 +11,12 @@ import MatrixRustSDK
 
 enum MessageForwardingScreenViewModelAction {
     case dismiss
-    case sent(roomID: String)
+    case sent(roomIDs: [String])
 }
 
 struct MessageForwardingScreenViewState: BindableState {
     var rooms: [MessageForwardingRoom] = []
-    var selectedRoomID: String?
+    var selectedRoomIDs = [String]()
     var bindings = MessageForwardingScreenViewStateBindings()
 }